Self-braking winch drive



5 July 3, 1945.

B. M. CRAWFORD SELF-BRAKING WINCH DRIVE Filed March 13, 1944 a Sheets-Sheet 1 I INVENTOR.

ayBEqrW/IZ CZAWFOPO, i y %W%TORNEYS.

July 3, 1945- B. M. CRAWFORD SELF-BRAKING WINCH .DRIVE Filed Marbh 13, 1944 s Sheets-Sheet 2 I i fllil Barn AZ C734 NTQR. WFOEO, Y

ATTORNEYS.

Jul 3, 1945. B, A F RD 2,379,477 I SELF-BRAKING WINCH DRIVE r 1944 s Shegts-Sheef s Filed March 13,

35477 CPAWF'OEDI Patented July 3, 1945 UNITED STATES -PATEYNT OFFICE a 2,379,477 j] I SELF-BRAKING WINCH DRI E v v 'Beatty M. lrawford Santa-Ana CaIif. ApplicationMarch .13, 1944,:Seria1No. 526,289.

3 Claims. (01. 192-4)- This invention relates toa self-braking winch drive and like constructions. a

The invention has been'primarily designed for use in conjunction with a: power mast andboom vhoist such asis disclosed inmy cor-pending application Serial No. 495,185 filed July 17, 1943,.a-lthough it may be used in conjunction with other similar constructions. i

In various types of constructions it is desirable to provide a drive whereby a winch or other driven element may be power driven or forcibly rotated in either direction and upon disconnecting the driving connection between the winch and the source of power to immediately-and automatically brake the winch to hold it against continued rotation in either direction. .A device of this-character is highly desirable on hoists of various kinds where the load may be raised or ,low-

ered by means of a winch and on disconnecting the driving connection between the source of.

.power, and the Winch the winch will 'be .held againstcontinued rotation so that the load will not be dropped but will be maintainedin the position where it was at the time that the driving connection was broken. y

Another object of the invention-is to provid simple," sturdy'and, economical construction enabling the above mentioned functions to be easily andsmoothly performed, wherein there are relatively few moving parts, all of which are so "designed that they'cannot readily get out of order or require repair or replacement.

With the foregoing and other objects in view which will be made manifest-in the following detail description and specifically pointed out in the appended claims, reference i had t the accompanying drawings for an illustrative embodiment of the invention, wherein,

Fig. 1 is a partial view of a truck body illustrating a power mast. and boom hoist such as is disclosed in my co-pending application, mounted ving connection between the :source of powerand :thewincnw Eig.';5 .is a view similar .toiFig. 4 but illustrating :the position assumed :by :the parts'when-in brakin position. v

Referring tothezaccompanying drawings where- .in similar reference characters designate similar parts throughout, 10 indicates :a truck body on which is mounted a suitable hoist, the mast of which is indicated generally at H and the EbOOm.

of, which, is indicated generally :at 112. The mast is made up .of telescopic sectionsso that it may be raised and lowered and some Of these sections thereon and illustrating the mechanism embodying the present invention as having been applied thereto.

Fig. 2 is a top plan view of a portion of the truck chassis illustrated in Fi 1, the parts being illustrated in horizontal section. This view may be regarded as having been taken substantially upon the line 2-2 upon Fig. 1.

Fig. 3 is a vertical section through the lower portion of the mast of the hoist disclosed in my co-pending' application and illustrating parts of the drive mechanism embodying the present invention as having been associated therewith.

Fig. 4 is a partial view illustrating the position assumed by the mechanism in providing a drivaffords a braking surface.

.are adaptedgto be rotated such-asby a wormfl mounted on a shaftl4 so as .to swing the boom 12 about a veritical :axis through the mast. On the boom there is illustrated a trolley l5 apart of which canbelowered fromthe ,endof the boom as is disclosed in my co-pendingapplication. A

cable 1 6 extends upwardly through the .mast and serves to not only raise and lower sections of the mast H but to raise and lower thatportion of thetrolley which is suspended from the lbojom.

It also serves to draw the trolley inwardly along the length of the boom. Cable J'B- isattached to and is adapted to be wound up and unwoundtherefrom.v

.Shaft [8 which constitutes the source or "the .on .awinch 11 power for the drive embodying the present, in-

vention isdrive'n byalpower take-off at the transmission of the truck. It may be rotated, jhow- I ever, by any other suitable source of powerand is adapted to .be rotated when .operatingcontinuously in the same direction. On this shaft there are two opposed spaced disks I9 and 20, each of which is engageable by friction disks or driven disks 2| and 22 disposed therebetween. Disk 2| is mounted on a shaft 23 which is'connected by gearing 24 to the winch l1. Disk 22 is mounted on shaft 25 Which is connected by gearin 26 to shaft M on which worm I3 is mounted. The

shafts 23 and 25 are mounted on standards 26 which are equipped at their lower ends with feet 21 that terminate at their ends in toes28 and 29. Spring actuated bolts 30 extend through the feet and through a suitable supporting structure 3| urging th feet downwardly so that the disks 2| and 22 are normally urged into positions wherein they are in peripheral engagement with the supporting structure 3| that constitutes or thus The upper ends of the standards 26 are slidable in grooves 32. The

standards 26 have operating rods 33 and 34 connected thereto and these operating rods are in turn connected to operating levers 35 that are suitably located, such as adjacent the rear of the truck body as shown on Fig. 1.

The operation and advantages of the above described construction are as follows: Whenever it is desired to wind up cable I6 on the winch or drum I1, operating lever 35 which operates the standard 25 On which disk 2| is mounted, may be forced forwardly. This causes the upper end of standard 26 that supports disk 2| to slide forwardly in groove 32, the standard rocking or tilting on toe 29. The periphery of disk 2| is thus lifted out of engagement with supporting structure 3| and is brought into engagement with drivingdisk 20 whereby a frictional drive is established between shaft l8. and the drum I1. When cable l6 has been wound up on the drum the desired distance, operating lever 35 maybe released. This permits the spring actuated bolts 30 to become effective to return the standardZG- to its normal neutral position. In this position disk 2| has disengaged disk 20 and has been caused to re-engage supporting structure 3|. The disk 2| is thus peripherally held against continued rotation and automatically locks the drum l1 against continued rotation and against unwinding of the cable l6 therefrom. Conversely when operating lever 35 is pulled rearwardly standard 26 is caused to have its upper end slide rearwardly through groove 32 and will rock about toe 28 as'a center. Disk 2| is thus caused to disengage structure 3| andto frictionally engage disk l9 whereby winch or drum, I! is reversely rotated so as to unwind cable -|B therefrom. Release of lever 35 causes the spring actuated bolts 3|] to again become effective to return the parts to normal or neutral position, wherein disk 2| is frictionally held or braked against further rotation and consequently dru-m I1 is automatically locked.

In a similar manner, disk 22 may be caused to optionally engage either disk 20 or disk I!) to rotate shaft M in either direction. Whenever its operating lever 35 is reIeased disk 22 will be automatically caused to re-engage supporting structure 3| and thus lock shaft l4 against con-s shaft l8. Whenever the operating lever that is used to establish the driving connection between the disks is released, the driven disk 2| or 22 as the case may be is instantly and automatically returned to braking position wherein it can no longer rotate. In this manner control of the hoist is maintained at all times.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the ap pended claims.

I claim:

1. A device of the class described, comprising a pair of spaced drive disks, a driven disk between the drive disks adapted to be optionally brought into frictional engagement with either of the drive disks so as to be driven thereby in either direction, braking means also engageable by the driven disk, and means normally urging the driven disk into engagement with the brakin means so that when the driven diskis released from engagement with one of the drive disks it will be automatically braked.

2. A device of the class described comprising a pair of spaced drive disks, a driven disk between the drive discs adapted to be optionally brought into frictional engagement with either of the drive disks so as to be driven thereby in either direction, a standard supporting the driven disk, said standard having a foot thereon terminating at its ends in toes, means yieldably urging the standard into a position wherein the driven disc is out of engagement with the drive disks, means serving to brake the driven disk and into engagement with which the driven disk is urged by said means, and means for tilting the standard about either of said toes.

3. A device of the class described comprising a pair of spaced drive discs, a driven disc between the drive discs adapted to be optionally brought into frictional engagement with either of the drive discs so as to'be driven thereby in either direction, a standard supporting the drivendisc, said standard being tiltable about either ot'two spaced points to bring the driven disc into engagement with either of the drive discs, means yieldably urging the standard into a position wherein the driven disc is out of engagement with the drive discs, means serving to brakev the driven disc and into engagement with which the driven disc is urged by said means, and means for tilting the standard.

BEAT'I'Y M. cRAWFoRD. 

